Check valve with flash seal

ABSTRACT

Check valve assemblies for fluid flow sets and devices are provided. The check valve assembly includes a housing having an inlet body and an outlet body. The inlet body includes a fluid inlet, a first seal bead having a first height, a second seal bead having a second height and a central channel. The outlet body includes a fluid outlet and a stem having a centering post, the centering post received by the central channel of the inlet body. A seal has an inner ring with a first thickness and an outer ring with a second thickness less than the first thickness. The inner ring is engaged with the first seal bead and the outer ring is engaged with the second seal bead in a fully sealed position of the check valve assembly. Fluid flow sets and methods for manufacturing check valve assemblies are also provided.

CROSS-REFERENCES TO RELATED APPLICATIONS

N/A

BACKGROUND

Check valves are used in the medical field in devices for controllingfluid flow to a patient, such as for fluid flow from an intravenous (IV)gravity or pump set. Typical check valves are susceptible to low flowleakage if particulate becomes caught between the elastomeric seal andthe seal bead. Having dual seal beads provides challenges because theseal beads need to be exactly the same height in order to eliminate apossible gap that would allow leakage. It is desirable to provide amedical fluid flow check valve that prevents low flow leakage, thusimproving safety and reducing risks.

SUMMARY

The present disclosure provides medical fluid flow check valves havingdual sealing rings.

In one or more embodiments, a check valve assembly is provided. Thecheck valve assembly includes a housing having an inlet body. The inletbody includes a fluid inlet, a first seal bead having a first height, asecond seal bead having a second height and a central channel. Thehousing also includes an outlet body. The outlet body includes a fluidoutlet and a stem having a centering post, the centering post configuredto be received by the central channel of the inlet body. The check valveassembly also includes a seal having an inner ring having a firstthickness and an outer ring having a second thickness less than thefirst thickness. The inner ring is engaged with the first seal bead andthe outer ring is engaged with the second seal bead in a fully sealedposition of the check valve assembly.

In one or more aspects, the first height of the first seal bead is lessthan the second height of the second seal bead. In one or more aspects,the first height of the first seal bead and the first thickness of theinner ring equals the second height of the second seal bead and thesecond thickness of the outer ring. In one or more aspects, the firstseal bead is a circular rib extending orthogonally from an inner surfaceof the inlet body and disposed around the central channel. In one ormore aspects, the second seal bead is a circular rib extendingorthogonally from the inner surface of the inlet body and disposedconcentrically around the first seal bead. In one or more aspects, adiameter of the inner ring is greater than a diameter of the first sealbead and a diameter of the outer ring is greater than a diameter of thesecond seal bead.

In one or more aspects, an end surface of one of the first seal bead andthe second seal bead is angled. In one or more aspects, only a pointportion of the end surface is engaged with the seal in the fully sealedposition of the check valve assembly. In one or more aspects, the sealis coupled to the centering post via a central hole of the seal. In oneor more aspects, the stem includes a shoulder and the inner ring of theseal is engaged by the shoulder. In one or more aspects, the seal issandwiched between the shoulder of the stem and an end surface of thecentral channel. In one or more aspects, the inlet body and the outletbody are sealed together.

In one or more aspects, one of the inlet body and the outlet body isconfigured to couple with intravenous tubing. In one or more aspects, aflexibility of the inner ring determines a cracking pressure for thecheck valve assembly. In one or more aspects, the inner ring is flexedaway from the first seal bead and the outer ring is flexed away from thesecond seal bead in an open fluid flow position of the check valveassembly. In one or more aspects, the outer ring is engaged with thesecond seal bead and the inner ring is flexed away from the first sealbead in a partially sealed position of the check valve assembly.

In one or more embodiments, a method of manufacturing the abovedescribed check valve assembly is provided. The method includes couplingthe seal to the stem, wherein the centering post is inserted into acentral hole of the seal and the seal rests on a shoulder of the stem.The method also includes connecting the inlet body to the outlet body,wherein the outer ring of the seal is loaded by the second seal bead.The method further includes ultrasonically welding the inlet body to theoutlet body, wherein the inner ring of the seal is secured between theshoulder of the stem and an end surface of the central channel of theinlet body, and wherein the inner ring of the seal is loaded by thefirst seal bead.

In one or more embodiments, a fluid flow set is provided. The fluid flowset includes a fluid inlet tube, a fluid outlet tube and a check valveassembly. The check valve assembly includes a housing having an inletbody coupled to an outlet body, the inlet body having a fluid inlet, acentral channel and a first seal bead having a different height than asecond seal bead, and the outlet body having a fluid outlet and acentering post, the centering post received by the central channel. Thecheck valve assembly also includes a seal coupled to the centering post,the seal having an inner ring and an outer ring where the outer ring isless thick than the inner ring. The inner ring is engaged with the firstseal bead and the outer ring is engaged with the second seal bead in afully sealed position of the check valve assembly. The inner ring isflexed away from the first seal bead and the outer ring is flexed awayfrom the second seal bead in an open fluid flow position of the checkvalve assembly. The outer ring is engaged with the second seal bead andthe inner ring is flexed away from the first seal bead in a partiallysealed position of the check valve assembly.

In one or more aspects, the first seal bead is a circular rib extendingorthogonally from an inner surface of the inlet body and disposed aroundthe central channel, and wherein the second seal bead is a circular ribextending orthogonally from the inner surface of the inlet body anddisposed concentrically around the first seal bead. In one or moreaspects, an end surface of each of the first seal bead and the secondseal bead is angled, and wherein only a portion of each end surface isengaged with the seal in the fully sealed position of the check valveassembly.

Additional features and advantages of the disclosure will be set forthin the description below and, in part, will be apparent from thedescription or may be learned by practice of the disclosure. Theobjectives and other advantages of the disclosure will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding of the disclosure and are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosure andtogether with the description serve to explain the principles of thedisclosure.

FIG. 1 depicts a schematic view of a typical assembled infusion set.

FIG. 2 is a perspective exploded view of an example check valve,according to some aspects of the disclosure.

FIG. 3 is a cross-sectional perspective view of the check valve of FIG.2, according to some aspects of the disclosure.

FIG. 4 is a partial cross-sectional perspective view of the check valveof FIG. 2 in a pre-assembled state, according to some aspects of thedisclosure.

FIG. 5 is a front view of the check valve of FIG. 4, according to someaspects of the disclosure.

FIG. 6 is a partial cross-sectional perspective view of the check valveof FIG. 2 in an assembled state, according to some aspects of thedisclosure.

FIG. 7 is a front view of the check valve of FIG. 6, according to someaspects of the disclosure.

FIG. 8 is a perspective view of a check valve seal, according to someaspects of the disclosure.

FIG. 9 is a front view of the check valve seal of FIG. 8, according tosome aspects of the disclosure.

FIG. 10 is a schematic view of the check valve of FIG. 7 in an open flowstate, according to some aspects of the disclosure.

DETAILED DESCRIPTION

The detailed description set forth below describes variousconfigurations of the subject technology and is not intended torepresent the only configurations in which the subject technology may bepracticed. The detailed description includes specific details for thepurpose of providing a thorough understanding of the subject technology.Accordingly, dimensions are provided in regard to certain aspects asnon-limiting examples. However, it will be apparent to those skilled inthe art that the subject technology may be practiced without thesespecific details. In some instances, well-known structures andcomponents are shown in block diagram form in order to avoid obscuringthe concepts of the subject technology.

It is to be understood that the present disclosure includes examples ofthe subject technology and does not limit the scope of the appendedclaims. Various aspects of the subject technology will now be disclosedaccording to particular but non-limiting examples. Various embodimentsdescribed in the present disclosure may be carried out in different waysand variations, and in accordance with a desired application orimplementation.

As shown in FIG. 1, a typical infusion set 30 may include a drip chamber40, a check valve 50, a roller clamp 60 and Y-junctions 70, allconnected together by tubing 20. A typical infusion set 30 can includeadditional infusion components (e.g., pinch clamps, filters) and can beformed of any combination of components and the tubing 20.

Check valve 50 is typically formed from flexible (e.g., elastomeric)seals mounted within a fluid flow housing. Typically, the flexible sealis mounted such that the seal engages a seal bead in the housing in thesealed position and flexes away from the seal bead in an open flowposition. However, if a particulate in the fluid becomes caught betweenthe seal and the seal bead, a gap will remain between the seal and theseal bead when the check valve 50 returns to the sealed position. Thisgap allows for leakage (e.g., low flow leakage) of fluid when the checkvalve 50 is supposed to be fully sealed to prevent any fluid flow.

According to aspects of the disclosure, a check valve assembly isprovided with a seal having dual sealing rings and a housing having dualseal beads. The outer seal prevents particulate (e.g., grit) fromreaching the inner seal, thus allowing the inner seal to fully close andto seal off fluid flow.

FIGS. 2-10 illustrate a check valve assembly shown as check valve 100,according to some aspects of the disclosure. The check valve 100includes a housing 110 having an inlet body 120, an outlet body 130 anda seal 140.

The inlet body 120 has a fluid inlet 122 configured to connect with afluid source (e.g., IV bag, infusion pump, needleless syringe) via an IVtube (e.g., tubing 20). The inlet body 120 includes a first seal bead124 and a second seal bead 126, each disposed on an inner surface 121 ofthe inlet body 120. The first and second seal beads 124, 126 may beconfigured as cylindrical ribs or teeth, for example. As shown in FIG.3, the first seal bead 124 is a circular rib disposed around a centralchannel 128 in the inlet body 120. The central channel 128 has an endsurface 129.

As shown in FIG. 5, the first seal bead 124 has an inner diameter D₁ anda height H₁. The second seal bead 126 is a circular rib disposedconcentrically around the first seal bead 124, the second seal bead 126having an inner diameter D₂ and a height H₂. Here, the height H₂ isgreater than the height H₁ so that the second seal bead 126 extendsfurther away from the inner surface 121 than does the first seal bead124. In some aspects of the disclosure, an end surface 123 of the firstseal bead 124 and/or an end surface 125 of the second seal bead 126 isangled such that only a point portion of the end surface 123, 125engages with the seal 140 when the check valve 100 is in a fully sealed(e.g., closed) position.

The outlet body 130 has a fluid outlet 132 configured to connect with adownstream fluid component (e.g., roller clamp 60). The outlet body 130includes a stem 134 having a centering post 136 and a shoulder 138, thecentering post 136 is configured to be received by the central channel128 of the inlet body 120.

The seal 140 includes an inner ring 142 and an outer ring 144. The innerring 142 has a thickness T₁ and the outer ring 144 has a thickness T₂,where thickness T₁ is greater than thickness T₂ (see FIG. 9). The innerring 142 has a diameter D_(S1) and the outer ring 144 has a diameterD_(S2), where diameter D_(S2) is greater than diameter D_(S1). Thediameter D_(S1) of the inner ring 142 of the seal 140 is greater thanthe inner diameter D₁ of the first seal bead 124, and the diameterD_(S2) of the outer ring 144 of the seal 140 is greater than the outerdiameter D₂ of the second seal bead 126. The seal 140 also includes acentral hole 146 that mounts on the centering post 136 of the outletbody 130 and a portion of the inner ring 142 that rests on the shoulder138 of the outlet body 130. The seal 140 may be formed of any flexiblematerial (e.g., silicone), where the inner ring 142 is somewhat flexibleand the outer ring 144 is thinner and more flexible. For example, theouter ring may be as thin as mold flash.

To assemble the check valve 100, the seal 140 is coupled to/mounted onthe centering post 136 of the outlet body 130 via the central hole 146of the seal 140, where the inner ring 142 rests on the shoulder 138 ofthe outlet body 130. As shown in FIGS. 4 and 5, the inlet body 120 iscoupled to/mounted on the outlet body 130, which causes the outer ring144 to be engaged and loaded by the second seal bead 126. As shown inFIGS. 6 and 7, the inlet body 120 and the outlet body 130 may then besealed together (e.g., ultrasonic welding), which causes the inner ring142 to be sandwiched and/or secured between the shoulder 138 of theoutlet body 130 and the end surface 129 of the central channel 128, andfurther causes the inner ring 142 to be engaged and loaded by the firstseal bead 124. Thus, during assembly of the check valve 100, the outerring 144 is loaded first and the inner ring 142 is loaded second. Insome aspects of the disclosure, the inner ring 142 and the outer ring144 have different preload forces.

As shown in FIG. 10, the check valve 100 is in an open or fluid flowmode when fluid enters through the fluid inlet 122 with sufficient forceto force the inner ring 142 and the outer ring 144 away from the firstseal bead 124 and the second seal bead 126, respectively. Thus, theinner ring 142 is flexed away from the first seal bead 124 and the outerring 144 is flexed away from the second seal bead 126 in this open fluidflow position of the check valve assembly 100. The fluid flows throughthe interior volume 112 of the housing 110 and out the fluid outlet 132of the outlet body 130. When the fluid pressure decreases or ceases(e.g., fluid flow slows or stops), the check valve 100 moves to a closedposition.

As the check valve 100 closes, the outer ring 144 closes first byflexing back to its starting position to engage the second seal bead126. This occurs because the outer ring 144 is thinner and more flexiblethan the inner ring 142, thus causing the outer ring 144 to flex fasterand/or through a great range of motion than the inner ring 142. Byclosing first, the outer ring 144 creates an initial seal that preventsparticulate or grit from reaching the inner ring 142. Thus, the outerring 144 is engaged with the second seal bead 126 and the inner ring 142is still flexed away from the first seal bead 124 in this partiallysealed position of the check valve assembly 100.

After the outer ring 144 closes, the inner ring 142 then closes byflexing back to its starting position to engage the first seal bead 124.Thus, the inner ring 142 is able to close completely because of theabsence of particulate or grit caused by the earlier sealing of theouter ring 144. Thus, the inner ring 142 is engaged with the first sealbead 124 and the outer ring 144 is engaged with the second seal bead 126in this fully sealed position of the check valve assembly 100.

For the seal 140, the inner ring 142 is the primary seal and the outerring 144 is the secondary seal. Characteristics of the inner ring 142primary seal determines the cracking pressure of the check valve 100(e.g., the amount of fluid pressure required to open or crack the seal140), such as the flexibility of the inner ring 142, for example. Insome aspects of the disclosure, the cracking pressure is determined bythe inner ring 142 because the outer ring 144 secondary seal is verythin and has little resistance to the fluid pressure. In some aspects ofthe disclosure, the cracking pressure is determined by the inner ring142 because the inner ring 142 primary seal is sealed against the firstseal bead 124, which prevents any fluid from reaching the outer ring 144secondary seal. Once the cracking pressure is reached in the check valve100, both the inner ring 142 primary seal and the outer ring 144secondary seal move away from the first seal bead 124 and the secondseal bead 126 (e.g., open up) to allow fluid to flow past the seal 140.

The operation of the check valve 100 may be varied by modifyingdifferent elements. For example, increasing/decreasing either or boththe thickness T₁ of the inner ring 142 and the thickness T₂ of the outerring 144, increasing/decreasing either or both the diameter D₁ of theinner ring 142 and the diameter D₂ of the outer ring 144,increasing/decreasing either or both the height H₁ of the first sealbead 124 and the height H₂ of the second seal bead 126, and usingvarious materials to change the stiffness or flexibility of either orboth the inner ring 142 and the outer ring 144 may change the crackingpressure and/or flow characteristics of the check valve 100.

It is understood that any specific order or hierarchy of blocks in themethods of processes disclosed is an illustration of example approaches.Based upon design or implementation preferences, it is understood thatthe specific order or hierarchy of blocks in the processes may berearranged, or that all illustrated blocks be performed. In someimplementations, any of the blocks may be performed simultaneously.

The present disclosure is provided to enable any person skilled in theart to practice the various aspects described herein. The disclosureprovides various examples of the subject technology, and the subjecttechnology is not limited to these examples. Various modifications tothese aspects will be readily apparent to those skilled in the art, andthe generic principles defined herein may be applied to other aspects.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically so stated, but rather “one or more.”Unless specifically stated otherwise, the term “some” refers to one ormore. Pronouns in the masculine (e.g., his) include the feminine andneuter gender (e.g., her and its) and vice versa. Headings andsubheadings, if any, are used for convenience only and do not limit theinvention.

The word “exemplary” is used herein to mean “serving as an example orillustration.” Any aspect or design described herein as “exemplary” isnot necessarily to be construed as preferred or advantageous over otheraspects or designs. In one aspect, various alternative configurationsand operations described herein may be considered to be at leastequivalent.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “or” to separate any of the items, modifies thelist as a whole, rather than each item of the list. The phrase “at leastone of” does not require selection of at least one item; rather, thephrase allows a meaning that includes at least one of any one of theitems, and/or at least one of any combination of the items, and/or atleast one of each of the items. By way of example, the phrase “at leastone of A, B, or C” may refer to: only A, only B, or only C; or anycombination of A, B, and C.

A phrase such as an “aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples. A phrase such as an aspectmay refer to one or more aspects and vice versa. A phrase such as an“embodiment” does not imply that such embodiment is essential to thesubject technology or that such embodiment applies to all configurationsof the subject technology. A disclosure relating to an embodiment mayapply to all embodiments, or one or more embodiments. An embodiment mayprovide one or more examples. A phrase such an embodiment may refer toone or more embodiments and vice versa. A phrase such as a“configuration” does not imply that such configuration is essential tothe subject technology or that such configuration applies to allconfigurations of the subject technology. A disclosure relating to aconfiguration may apply to all configurations, or one or moreconfigurations. A configuration may provide one or more examples. Aphrase such a configuration may refer to one or more configurations andvice versa.

In one aspect, unless otherwise stated, all measurements, values,ratings, positions, magnitudes, sizes, and other specifications that areset forth in this specification, including in the claims that follow,are approximate, not exact. In one aspect, they are intended to have areasonable range that is consistent with the functions to which theyrelate and with what is customary in the art to which they pertain.

It is understood that the specific order or hierarchy of steps,operations or processes disclosed is an illustration of exemplaryapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of steps, operations or processes may berearranged. Some of the steps, operations or processes may be performedsimultaneously. Some or all of the steps, operations, or processes maybe performed automatically, without the intervention of a user. Theaccompanying method claims, if any, present elements of the varioussteps, operations or processes in a sample order, and are not meant tobe limited to the specific order or hierarchy presented.

All structural and functional equivalents to the elements of the variousaspects described throughout this disclosure that are known or latercome to be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. § 112 (f) unless the element isexpressly recited using the phrase “means for” or, in the case of amethod claim, the element is recited using the phrase “step for.”Furthermore, to the extent that the term “include,” “have,” or the likeis used, such term is intended to be inclusive in a manner similar tothe term “comprise” as “comprise” is interpreted when employed as atransitional word in a claim.

The Title, Background, Summary, Brief Description of the Drawings andAbstract of the disclosure are hereby incorporated into the disclosureand are provided as illustrative examples of the disclosure, not asrestrictive descriptions. It is submitted with the understanding thatthey will not be used to limit the scope or meaning of the claims. Inaddition, in the Detailed Description, it can be seen that thedescription provides illustrative examples and the various features aregrouped together in various embodiments for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed subject matter requires morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed configuration or operation. The followingclaims are hereby incorporated into the Detailed Description, with eachclaim standing on its own as a separately claimed subject matter.

The claims are not intended to be limited to the aspects describedherein, but are to be accorded the full scope consistent with thelanguage claims and to encompass all legal equivalents. Notwithstanding,none of the claims are intended to embrace subject matter that fails tosatisfy the requirement of 35 U.S.C. § 101, 102, or 103, nor should theybe interpreted in such a way.

The invention claimed is:
 1. A check valve assembly, comprising: a housing comprising: an inlet body comprising: a fluid inlet; a first seal bead having a first height; a second seal bead having a second height; and a central channel; and an outlet body comprising: a fluid outlet; and a stem having a centering post, the centering post configured to be received by the central channel of the inlet body; and a seal comprising: an inner ring having a first thickness; and an outer ring having a second thickness less than the first thickness, wherein the inner ring is engaged with the first seal bead and the outer ring is engaged with the second seal bead in a fully sealed position of the check valve assembly.
 2. The check valve assembly of claim 1, wherein the first height of the first seal bead is less than the second height of the second seal bead.
 3. The check valve assembly of claim 1, wherein the first height of the first seal bead and the first thickness of the inner ring equals the second height of the second seal bead and the second thickness of the outer ring.
 4. The check valve assembly of claim 1, wherein the first seal bead is a circular rib extending orthogonally from an inner surface of the inlet body and disposed around the central channel.
 5. The check valve assembly of claim 4, wherein the second seal bead is a circular rib extending orthogonally from the inner surface of the inlet body and disposed concentrically around the first seal bead.
 6. The check valve assembly of claim 1, wherein a diameter of the inner ring is greater than a diameter of the first seal bead and a diameter of the outer ring is greater than a diameter of the second seal bead.
 7. The check valve assembly of claim 1, wherein an end surface of one of the first seal bead and the second seal bead is angled.
 8. The check valve assembly of claim 7, wherein only a point portion of the end surface is engaged with the seal in the fully sealed position of the check valve assembly.
 9. The check valve assembly of claim 1, wherein the seal is coupled to the centering post via a central hole of the seal.
 10. The check valve assembly of claim 1, wherein the stem includes a shoulder and the inner ring of the seal is engaged by the shoulder.
 11. The check valve assembly of claim 10, wherein the seal is sandwiched between the shoulder of the stem and an end surface of the central channel.
 12. The check valve assembly of claim 1, wherein the inlet body and the outlet body are sealed together.
 13. The check valve assembly of claim 1, wherein one of the inlet body and the outlet body is configured to couple with intravenous tubing.
 14. The check valve assembly of claim 1, wherein a flexibility of the inner ring determines a cracking pressure for the check valve assembly.
 15. The check valve assembly of claim 1, wherein the inner ring is flexed away from the first seal bead and the outer ring is flexed away from the second seal bead in an open fluid flow position of the check valve assembly.
 16. The check valve assembly of claim 1, wherein the outer ring is engaged with the second seal bead and the inner ring is flexed away from the first seal bead in a partially sealed position of the check valve assembly.
 17. A method of manufacturing the check valve assembly of claim 1, the method comprising: coupling the seal to the stem, wherein the centering post is inserted into a central hole of the seal and the seal rests on a shoulder of the stem; connecting the inlet body to the outlet body, wherein the outer ring of the seal is loaded by the second seal bead; and ultrasonically welding the inlet body to the outlet body, wherein the inner ring of the seal is secured between the shoulder of the stem and an end surface of the central channel of the inlet body, and wherein the inner ring of the seal is loaded by the first seal bead.
 18. A fluid flow set, comprising: a fluid inlet tube; a fluid outlet tube; and a check valve assembly, comprising: a housing having an inlet body coupled to an outlet body, the inlet body having a fluid inlet, a central channel and a first seal bead having a different height than a second seal bead, and the outlet body having a fluid outlet and a centering post, the centering post received by the central channel; and a seal coupled to the centering post, the seal having an inner ring and an outer ring where the outer ring is less thick than the inner ring, wherein the inner ring is engaged with the first seal bead and the outer ring is engaged with the second seal bead in a fully sealed position of the check valve assembly, wherein the inner ring is flexed away from the first seal bead and the outer ring is flexed away from the second seal bead in an open fluid flow position of the check valve assembly, and wherein the outer ring is engaged with the second seal bead and the inner ring is flexed away from the first seal bead in a partially sealed position of the check valve assembly.
 19. The fluid flow set of claim 18, wherein the first seal bead is a circular rib extending orthogonally from an inner surface of the inlet body and disposed around the central channel, and wherein the second seal bead is a circular rib extending orthogonally from the inner surface of the inlet body and disposed concentrically around the first seal bead.
 20. The fluid flow set of claim 18, wherein an end surface of each of the first seal bead and the second seal bead is angled, and wherein only a portion of each end surface is engaged with the seal in the fully sealed position of the check valve assembly. 